CHINA RIVETING AND REPAIRING

by Paul N. Hasluck c1940's

In mending china it is questionable whether anything short of rivets should be used, because repairs carried out with the aid of cement are always more or less in danger of falling to pieces with ordinary usage. Of course, ch ina or glass that is rarely handled may sometimes be suitably repaired with cement, and the appearance of rivets on a priced piece of pottery will then be avoided. Several good cements can be made at home.

Fig. 1 - Drill for China Repairing

The combination of shellac and rectified spirit known as Chinese cement is a very strong medium, and is made by dissolving 1/4lb. of the best pale orange shellac in 3 oz. of strong spirit. The shellac should be pounded up fine and placed in a stoppered or corked bottle with the spirit, in a warm place , and the mixture should not be used until the shellac has become thoroughly dissolved. The real Chinese cement however, as made by Chinamen, is produced by pounding glass to a very fine powder, then sieving it through silk, and afterwards mixing and grinding it with albumen. Ornaments repaired with this medium (providing heat is not applied) will not readily separate at the joint. White-lead will resist boiling water, and make an exceptionally strong repair if it is allowed to set before the article is brought into use; but it will take several weeks to harden properly. It should always be used carefully, as traces of it are difficult to remove when allowed to harden on an exposed part. Several of the advertised cements are good, but where ornaments only are concerned, probably none is cleaner, stronger, more suitable, or more easily applied than is in glass dissolved in acetic acid. The great drawback of this is that it will not stand hot water. It should be evenly applied to the broken edges with a camel-hair brush, and sets hard in twelve or fourteen hours.

It is the way in which the cement is used, rather than the kind of cement employed, that is the important element in making a strong joint. Many people are afraid to heat delicate china and glass ornaments sufficiently. The parts should be heated in the oven, as the cement begins to harden immediately it comes in contact with cold materials, and therefore produces a "set" layer between the broken parts. If possible, the article joined should be bound tightly with tape until properly set, and should be placed in some cool apartment where it is not likely to be shaken or upset.

Fig. 2 - Drill Arm

Always undertake the repair as soon as possible after the article is broken, as then the edges are not in any way damaged, and a close joint results. Shellac alone makes an extremely strong joint if the broken parts are sufficiently heated to fuse it when applied; but, unfortunately, it leaves a very noticeable dark line on white china.

Fig. 3 - Diamond Bit

Riveting is the most substantial way of repairing broken articles, but entails a small outlay for the drill, hammer, wire-cutting pliers, file, and material for the rivets. The drill complete is illustrated at Fig. 1. To construct it, a light steel spindle, 14 in. long, pointed at one end, will be required for the stock. A hole must be drilled through the head of this spindle to take the tape T, which is also fastened to the ends of the wooden arm A. This arm is bored (see Fig.2) so that it can easily pass up and down the spindle. A piece of box or ebony B (Fig. 1) should also be turned 2 1/4 in. in diameter, by 1 in. thick, and a hole slightly smaller than the steel rod drilled through it, when the block is ham m ered tightly into position. This hole must be drilled accurately, or the drill will wobble, and for this reason the hole should be drilled halfway through from each side. A still better method is to knock the wood on the spindle, and then true it up in a lathe.

Fig. 4 - Method of Working Drill

The drill bits (fig. 3) simply consist of tapering tin tubes with a diamond point cemented or soldered in one end. These tin tubes fit tightly over the cone end of the drill proper, but it is not an easy matter to set the diamond fragments, or sparks, in the tubes. The mouth of the tube should be not more than 3/32 in. in diameter, and should not commence to widen out into a cone under 1/2 in. from the end. Some measure of success can be obtained with well-tempered steel drills, if fine diamond powder moistened with oil is used as an abrasive, but neat holes are rarely produced, and surrounding glaze is frequently chipped off.

Fig. 5 - Section showing Position of Rivet Holes

To use the diamond drill the spin dle is twisted so that the tape winds itself round the stem, as illustrated in Fig 4. When the arm is pressed downwards, the tape unwinds and causes the spindle to revolve; then, if the hand is raised again at the crucial moment, the tape will immediately coil round the stem in the opposite direction, and thus be ready for another downward thrust of the arm. A little practice will soon enable the beginner to get a continuous motion. The operator sits, and always works the apparatus with the right hand only, leaving the left hand free to hold the glass or china rigidly against the thigh of the left leg. Before using the drill, always dip the point in oil, and bore all holes in the articles about 1/4 in. from the edge, at an angle so that they incline slightly towards the breakage (see Fig. 5). The position at which the holes are to be drilled should be very accurately marked, and care should be taken not to bore the holes straight through the material. If the finger is held underneath the part which is b eing drilled, the warmth will indicate how far the bit is through the china.

Fig. 6 - Rivet in Position

The clasps or rivets generally consist of 1/16 in. brass wire, with one side half filed away, so that a flat surface meets the article.

Fig. 7 - Distribution of Rivets on Plate

Of course, the thickness of the wire employed depends on the character of the article to be repaired. In the case of plates and similar goods, always fix the rivets on the back, as then they cannot be seen.

Fig. 8 - Rivet formed with Pliers

Fig. 6 shows the rivet in position after the repair is accomplished, and Fig. 7 represents the back of a broken plate, and illustrates how the rivets should be distributed. To make the rivets, first place one end of the filed wire in the mouth of a pair of pliers (see Fig. 8), and, on the nose of the tool, hammer the wire down a little past a right angle with the flat side.

Fig. 9 - Finished Rivet

Then carefully measure where the second bend ought to be, cut off the surplus wire, and bend down the second end, as in Fig. 9. Each rivet should fit the hole so tightly as to require gentle knocking into position with a very light hammer, or it will spring into position. If given a pull with the pliers. Take care that the ends of the rivet are not to long, as if this is the case it will not lie flat on the broken article. To complete the repair it is then only necessary to fill up the holes and cracks with plaster-of-Paris mixed with water to the consistency of cream, and either left white or coloured, according to the article being mended.

Fig. 10 - Arrangement of Rivets for V-piece Broken out of Plate

Fig. 10 shows the arrangement of rivets for a plate from which a V-piece has been broken out and which is badly cracked as well. Cement would effectively repair a jug broken as shown (see Fig. 11), but if rivets are used distribute them in the manner illustrated. The portion A had best not be tampered with, as it has a very slender hold on the rest of the article, and very little pressure would break it. A good waterproof cement for glass consists of 3 parts plaster-of-Paris, 3 parts Litharge, white-lead, and 1 part powdered resin - all by measure. When repaired for use, mix it into a paste (the 3 parts proper consistency depends on the purpose for which it is required) with boiled linseed oil. It sets hard in three days. To colour a cement, mix with it colouring mater to be purchased at any oil or colour stores. Winchell's cement is given as a universal cement 1/2 oz. O f white sugar, 1 1/2 oz. Fine starch, and 2 oz. Clear gum arabic. Crush the gum to a . Procure powder, then dissolve it in the quantity of water that would be used in laundry work for the quantity of starch mentioned, and afterwards dissolve both the starch and the sugar in the gum solution.

Fig. 11 - Distribution of Rivets for Broken Jug

Next place this mixture in some suitable receptacle, and place the latter in a saucepan of boiling water, leaving it thus until the starch becomes clear. The cement will then be ready for use, and should be of about the consistency of tar. If it is to be kept for some time, a few drops of oil of cloves or sassafras will prevent it becoming unfit for . Illustrations showing jug and vase repairs are presented by Figs. 12 and 13. If jugs are valuable and are used only as ornaments, cement may prove satisfactory for attaching handles, as the disfiguring effect of rivets is then avoided, but if the jugs have to be used (and the breakages allow such a plan to be adopted), fine wire rivets should be employed to strengthen the joints. When a thick handle is broken, china repairers often employ wire (not more than 1/2 in.long) to strengthen the joint without being visible.

Fig. 12 - Jug Repairs Fig 13 - Vase Repairs

As shown in Fig. 14, a handle, and the wire, after having its ends roughly notched (as shown in Fig. 15) by a file, is fixed in position with a very little plaster in the holes before the wire; if too much were used, some of the plaster would be forced out -of-Paris, which is placed of the holes by the wire, and would prevent a close join being made. The faces of the broken parts are also thinly smeared with suitable cement w hen the workman is ready to join the pieces.

Fig. 14 - Mending Jug Handle with Wire Fig. 15 - Wire Rivet with Ends Notched